Circuit breaker



Oct. 19, 1937. J G JACKSON 2,096,545

CIRCUIT BREAKER Filed- April 1, 1936 I5 Sheets-Sheet l i: INVENTOR.

J79}??? 6f J'acZson- ATTORNEY Oct. 19, 1937. J. G. JACKSON ,0

C IRGUIT BREAKER Filed. April 1, 1936 3 Sheets-Sheet 2 V INVENTOR- Jqfirz 6: 726175072,

ATTORNEY.

Oct. 19, 1937.

01301311 BREAKER, 3

Filed April 1, 1936 3 Sheets-Sheet 3 [1V V EN T 0R J55)? 8. kc/P5027,

J. G. JACKSON 2,096,545

Patented Oct. 1-9, 1937 PATENT, OFFICE cmcUrr BREAKER John (i. Jackson, Detroit, Mich assignor to Square D Company, Detroit, Mich, a corporation of Michigan Application April 1, 1936, Serial No. 72,035

. 10 Claims.

improved operc ting handle and mechanism actuated thereby for an .electric circuit breaker.

Another object of the invention is to provide a pivoted circuit breaker operating handle hav- 10 ing a cam surface moving an element rectilinearly and having stable and unstable portions for maintaining or permitting movement of the element.

Another object of the invention is to provide 15 an improved form-of guiding and stopping means for a releasable contact bar.

Another object of the invention is to provide an improved pivotal support for a contact bar which shall insure the proper relation of parts 20 when in circuit closed position.

Other objects an will be readily apparent to those skilled in the art from the following specification and appended drawings illustrating certain preferred embodi- 25 ments of the invention in which:

Figure l is a front elevational view of a circuit breaker assembly according to the present invention with certain parts broken away to show internal parts.

30 Figure 2 is a longitudinal sectional view taken on the line IIII of Figure 1.

Figure 3 is a fragmentary sectional view taken on the line IIIIII of Figure l.

Figure 4 is a view similar to Figure 3 show- 35 ing the parts in another position.

Figure 5 is afragmentary transverse sectional view taken on the line V -V of Figure 1.

Figure 6 is an enlarged view of a constructional detail. 40 Figure 7 is a fragmentary sectional view similar to Figures 3 and4 showing a modified form of operating handle.

The circuit breaker asherein illustrated and described embodies the main structural and opcrating features of that described in applicant's copending application, Serial No. 36,247, filed August 15, 1935, entitled Circuit breakers,and the present invention constitutes an improvement or a further development of the invention disclosed 59 therein.

As shown, the circuit breaker assembly comprises two units I and 2 mounted in juxtaposed relation within an enclosing box 8 having an openable cover, not shown, which may be hing- 'edly orotherwise mounted onthe box. These features of the invention identical construction and, as

shown, each comprises an enclosure having a cup-shaped insulating base 4 within which is generally centrally disposed a contact plate 5 carrying contact surfaces at its corners. Co- 5 operating with these contact surfaces are four individual floating contact bars 6 carrying contact surfaces at one and cooperating with the stationary contact surfaces and latched at the other end by bimetallic members I adjustably 10 supported on connectors 8 leading to the exterior of the circuit breaker enclosure. Compression springs 9 bias the bars 6 against the stationary contact surfaces and the bimetallic latches 1. The top edges of the bars 6 are provided with pairs of notches II and I2 and are received within slots I! in rectilinearly movable members H generally U-shaped in cross section. The longer legs of the elements I eng ge within the notches II at the top of the slots i3. Flexible leads i5 interconnect the free ends of the bimetallic latches and intermediate points on the bars 6. The elements I! and the bars 6 are provided with suitable-guiding surfaces, as more fully explained in the aforementioned copending application. t

The contact plate 6 may be disposed on a barrier wall dividing the lower portion of the base into two parts and the arc chamber adjacent the cooperating contact surfaces maybe provided.with suitable fibre barriers and openings but these'features form no part of the present invention and constitutethe invention described and claimed in a copending application, Serial No. 77,519, filed May 2, 1936.

A fibre sheet I6 is disposed over the top of the base and a cover I! preferably of steel is riveted or otherwise sealably secured to the base to, prevent access to the circuit breaker parts from the exterior. Terminal connectors l8 are 40 provided on ledges at the opposite ends of the exterior of the breaker and over the line terminals may be disposed a fibre shield is attached to the cover by a pair of screws 2|.

units may be of Pivotally supported as by means of shafts 22 I within recesses 23 in the side walls of the. base, i are operating handles 24 having interior operating portions 25. These interior portions bear against the top surfaces of the rectilinearly movable elements H and constitute cam. surfaces which upon rotation move the elements rectilinearly. The operating portions 25 are provided with flat" surfaces 26 and projections 30 which form stable supports for the elements I4 in a depressed position corresponding to the manual and with tips 21 for causing 'mounted in this manner left in Figure 2, corresponding to manual ofi engaged position under the end of the bar 6 bimetallic latch 1 oif position of the circuit breaker mechanism, a further movement of the elements M to reset the breaker nism after an automatic operation as will be more fully described hereinafter. The top corners of the elements l4 are beveled as at It and 20 to cooperate with the projections 30.'

The projections 30 bear against the bevels In in the manual oif position and this provides a yielding resistance to the initial movement of the operating handles toward on position. The bevels 20 provide clearance for the projections to properly position the handles in the on position. The portions 25 of the operating handles are provided with openings 28 into which project the ends of springs 29 serving to bias the handles against the members l4. The interior portions 25 of the handles may be provided with cutout portions 3| to provide for free movement of the springs with relation to the operating portion of the handles.

The units are mounted in juxtaposed relation within the box 3 by means of-studs 32 and when the studs on either unit are removed that unit may be readily moved sidewise. With the units the immediately juxtaposed handles on the separate units may be joined together for common movement to certain positions by means of a large manually engageable portion 33 disposed between the handles and having reduced end portions or pins 34 disposed within conical or otherwise elongated holes in the handles 24. It can readily be seen that once the units are in a juxtaposed position the manually engageable means 33 cannot be detached from the cooperating handles unless the studs 32 on one unit are released and this unit moved sidewise. N

The operation of the parts shown in Figures 1 to 5, inclusive, will now be explained.

nism at the right therein is in the normal on position. When the handle 24 is rotated to engage the fiat surface 26 and projection 30 with the rectilinearly movable-member N the parts will assumethe positions substantially shown at the position, with the movable contact surface moved to a disengaged position against the bias of the spring 9. This position constitutes a stable position which the parts will retain until the operating handle is moved in reversed direction to permit the movable contact surface to move into the bias of the spring 9. The spring 29 in the normal on positionof the device shown at the right in Figure 2 biases the handle 24 into engagement with the element l4 and biases this element within the notch l I in the bar 6. Upon the occurrence of an overload the will become heated and move to in Figure 3, thus unlatching and permitting it to rotate into the position shown in Figure 3. Here the .bar

the position shown is rotated about its engagement with the element mechascribed.

guiding meansso that as into an indicating position beyond the on position as shown in Figure 3.

To reset the mechanism after an automatic operation, the handle is rotated beyond the normal of! position into that shown in Figure 4, whereupon the tip 21 on the operating portion 25 of the handle engages the element l4 and forces it into the position shown. In this rotation of the handle the contact end of the bar 6 engages the bottom of the arc chamber and causes the bar to rotate about its into the position shown. When the handle is released from the position in Figure 4,.the parts will assume the position of normal off as shown at the left in Figure 2. To again close the circuit through the breaker the handle is rotated to the normal "on position whereupon the parts will assume the position shown at the right in Figure 2.

So far, the operation of .the individual breaker mechanisms in the breaker unit have been de- Where the immediately juxtaposed handles are joined together by the engageable portion 33, their movement to manual on, manual "ofi and reset positions will be substantially common and will take place by the proper manipulation of the element 33. However, due to the enlarged openings in the receive the pins 34, provision is made for a limited indemndent movement of the handles so that they may independently indicate their tripped position. The joined handles shown at the bottom of Figure -l are both in the ofi position. The joined handles in the upper part of Figure l and in Figure 5 are in diiferent positions and that shown at the left indicates the tripped position of the breaker of which it forms a part, while that at the right is still in the normal "on position. By this means it is possible to know which of the breakers has been automatically operated even though the handles are together for sub- As seen in Figure 2, the circuit breaker mechaan open side 35 permitting 'free rotation of the bar with respect to the element 14 in the released direction and with a projecting surface 36 engageable with the element H to restrict relative movement between opposite. direction. As the bar 6 moves into on position, the projecting surface 36 will engage element l4 and move it as far to the right as its guiding means will permit, or if the overlap between the bimetallic latch and the end of the bar has been too great, it will move the end of the bar with respect to the bimetallic latch after the play in the element l4 has been taken up. This insures the proper overlap of the bimetal I with the end of the bar and/or theproper positioning of the element M at the bimetal side of its the bimetal I warps it will not have to absorb this play before moving with respect to the end of the bar.

In Figure 7 is shown a slightly modified form of operating handle in which the manual '0 and reset positions are the same. In this handle, when the tip 21' engages the element l4 a stable condition is produced and in this position the conhandles 24 which.

the bar and element in the end of the bar from the bimetallic latch each time the contacts are moved to manual "01! position and as this may disturb the calibration of the breaker, the handle illustrated in Figures 1 to 5, inclusive, is preferred. The joining together of the handles shown in Eigure 7 may be the same as that shown in Figures 1 to 5, inclusive.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily appar'- ent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What is claimed is:

1. In an automatic electric circuit breaker, stationary and movable contacts, an element movable rectilinearly to move the movable contact, a pivoted manual operating member, said member including a cam surface engaging said element to move it rectilinearly in response to 1'0- tary movement of the member to engage and disengage said contacts, and automatic means for separating said contacts, rotary movement of said member causing said element to move rectilinearly to reset said automatic means after 7 an automatic separation.

2. In an automatic electric circuit breaker, stationary and movable contacts, means biasing said contacts together, a pivoted operating handle, a cam surface movable with said handle, an element movable rectilinearly against said biasing means to move the movable contact to a separated position, said cam surface engaging said element and ment of the handle into rectilinear movement of the element, said cam surface including a stable supporting portion for maintaining the movable contact in the separated position, andmeans for eilecting automatic separation of said I contacts in response to a current overload, said cam surface including an unstable portion beyond said stable position. for causing further movement of said element to effect resetting of the breaker mechanism after an automatic separation.

3. In an automatic electric circuit breaker, a stationary contact, a movable contact bar carrying a contact surface adjacent one end adapted to cooperate with said contact, current responsive latching means for the opposite end of the bar, biasing means intermediate the ends of the bar, a movable element engaging the bar interjacent the biasing means and said one end of the bar, a pivoted operating handle carrying a cam sur-- face adapted to engage and move said element, said cam surface including a stable portion maintaining the contact surface in a separated position while the bar is engaged by the latching means, said surface including a portion beyond said stable portion for'causing further movethe biasing means ment of the element to move said opposite end of the bar beyond said latching means into a resetting position.

4. In an automatic electric circuit breaker, a stationary contact, a movable contact bar carrying a contact surface adjacent one end adapted to cooperate with said contact, current responsive latching means for the opposite end of the bar,

biasing means intermediate the ends of the bar, a movable element engaging the bar interjacent and said one end of the bar, a pivoted'operating handle carrying a cam surface adapted to engage and move said element,

means biasing said surface against said element transforming rotary move- .ing said bar between the ment to move said opposite end of the bar beyond said latching tion.

5. In an automatic electric circuit breaker, a, stationary contact, a movable contact bar carrying a contactsurface adjacent one end adapted to cooperate with said contact, current responsive latching means for the opposite end of the bar, biasing means intermediate the ends of the bar, a movable element engaging the bar interjacent the biasing means and said one end of the'bar, a pivoted operating handle carrying a cam surface adapted to engage and move said element, means biasing said surface against said element and said element against said bar, said cam surface including a stable portion maintaining the contact surface in aseparated position'while the bar is engaged by the latching means, said surface including a portion beyond said stable portion for causing further movement of the element to move said opposite end of the bar beyond said latching means into a resetting position, said first mentioned biasing means causing a small movement of said element in its contact engaging direction when the bar is released upon a current overload to rotate the handle against its biasing means to a position beyond the normal contacts engaged position to indicate the automatic contacts separated condition of the breaker.

' 6. In an automatic electriccircuit breaker, stationary and movable contacts, means biasing said contacts together, means for effecting automatic separation of said contacts in response to overload, an element movable rectilinearly against said biasing means to effect separation of said contacts and to reset the mechanism after an automatic separation, a pivoted operating handle c r ying a cam surface engaging said element, the contacts separated and resetting positions of means into a resetting posisaid element being the same and corresponding to a stable position of the cam surface to maintain the contacts separated.

'7. In an automatic electric circuit breaker, a stationary contact, a contact bar carrying a contact surface at one and adapted to cooperate with said contact, current responsive latching means for the opposite end of said bar, means interjacent the ends of the bar biasing it against said contact and latching means, means pivotally engaging said bar interjacent the biasing means and contact surface, and a limiting stop engagpivot and the latching end and limiting its rotative movement when released. I

8. In an automatic electric circuit breaker, a, stationary contact, a contact bar carrying a cortact surface at one end adapted to cooperate with said contact, current responsive latching mea L3 for the opposite end of said bar, means inter- Jacent the ends of the bar biasing it against said contact and latching means, a notch in said interiacent the biasing means and contact surface, a rectilinearly" movable element received in latching means to limit 7 .5

' the rotation of the bar and assist in its proper positioning.

9. In an automatic electric circuit breaker, a stationary contact, a contact bar carrying a. contact surface at one end adapted to cooperate with said contact, current responsive latching means for the opposite end 0! said bar, means interjacent the ends of the bar biasing it against said contact and latching means, a notch in said bar interjacent the biasing means and contact sur- I face, a rectilinearly movable element received in said notch to move and guide said bar, said notch having an open side to permit free rotation of the bar in the automatic opening direction, and an interfering surface on the opposite side limiting free rotation of the bar in the opposite direction with respect to said element, said element Ming movable to rotate the bar into resetting position, movement of said bar to closed circuit podtion after reset causing said surface to engage the element and insure the proper positioning of the bar with respect to. the latching means.

10. In an automatic electric circuit breaker, a stationary contact, a contact bar carrying a contact surface at one end adapted to cooperate with said contact, current responsive latching means for the opposite end of said bar, biasing means interjacent the ends of the bar, means pivotally engaging said bar interjacent the biasing means and contact surface, said bar being freely rotatable with respect to said engaging means when released by said latching means, and means 1im-' iting the extreme position of rotation of the bar with respect to said engaging means in the opposite direction to ensure the proper positioning of the bar with respect to said engaging means and said latching means.

JOHN G. JACKSON. 

